The disclosed technology relates generally to data encoding, and more particularly to low-density parity check (LDPC) encoders.
With the continuing demand for high-reliability transmission of information in digital communication and storage systems, and with the rapid increase in available computational power, various coding and decoding techniques have been investigated and applied to increase the performance of those systems. One such coding technique, low-density parity check (LDPC) coding, was first proposed in the 1960s, but was not used until the late 1990s when researchers began to investigate iterative coding and decoding techniques.
LDPC codes are among the few known error control coding techniques capable of transmitting information at a rate close to the Shannon limit or channel-capacity. Currently, LDPC codes are considered co be the next-generation communication system encoding standard. LDPC codes can be regular or irregular, have a linear or cyclic encoding matrix, and can be decoded in a myriad of ways, ranging in complexity and error performance.
However, there are a few concerns with LDPC codes. The error floor of LDPC codes may be of particular concern; in several applications, low error floors are required. However, it may be difficult to implement a low error floor LDPC code without making the code block length large. Lengthy LDPC codes, on the other hand, may require large memory buffers and/or computational power, even though the parity-check matrix if sparse. Due to the potentially large memory and computational requirements of suitably powerful LDPC encoders, the flexibility of these LDPC encoders is typically lower than desired.